Hydraulically actuated clutch release bearing systems are presently coming into wide spread use in the automotive and light truck industry as an improvement over the conventional, all mechanical "cable" systems.
Some hydraulic clutch release systems are completely external of the bell housing, i.e. both the master cylinder and slave cylinder are outside the bell housing and the slave cylinder output member is mechanically connected to and/or acts upon a conventional clutch release bearing actuating fork located within the bell housing. The systems are generally referred to as "hang-on" systems.
Another system, generally known as the "concentric slave cylinder" or "CSC" system, locates the slave cylinder within the bell housing concentrically with the clutch axis. Among other advantages, it eliminates the need for the actuating fork. Such a system is shown in U.S. Pat. No. 4,620,625, assigned to the assignee of the present invention.
It is the latter system to which the present invention is most concerned, although it would offer certain similar advantages if used on the hang-on system. Both the CSC system and the hang-on system can be shipped to the point of installation as unfilled, or either can be pre-filled with hydraulic fluid, thereby avoiding the need to fill the system on the production line or thereafter.
In either case, whether filled or unfilled, the clutch release bearing and actuator are held together during shipment and installation by a strap which holds the actuator in a completely or partially contracted position. For convenience, it is normal to install the actuator while held in the contracted position. In certain applications, it may even be required where axial space limitations between the transmission and engine would otherwise preclude such installation. In current practice, after installation, the strap is either manually removed or broken upon initial operation of the hydraulic cylinder.
A problem with known prior art straps that are removed or broken after installation is that they are not reuseable if the hydraulically actuated clutch release bearing assembly must be removed for further repair or adjustment. Once the known prior art straps have been broken or removed, they serve no useful purpose. A single use retainer strap that only holds a hydraulic actuator in its contracted position during initial installation complicates reinstallation of the hydraulic clutch release bearing assembly.